Soil productivity evaluation for a long has been a major hotspot in soil science. In this article, research conducted to soil management practices on soil productivity indices and soybean performance in Makurdi, Benue state Nigeria is reported. The productivity index (PI) model is a measure of soil productivity. The basic assumption of PI model is that crop yield is a function of root development, which in turn is controlled by the soil environment. This research was conducted various farms in Markurdi. The factors used in this model included available water capacity, pH, bulk density, land slope, clay content, organic matter content and depth of root zone. Comparisons were made of PI values obtained for the selected sites. Results from the study show that PI model can be used efficiently to characterize soil productivity at specific site if accurate field data are available. Results from the research work revealed significantly higher average seed yield, plant height and leaf area in
1.1 Background of the Study
Good soil management is a key to sustainable farming practices. Generally, there is close link between good and profitable farming; improving/maintaining soil fertility and good environmental management. Dent et al. (2016) opined that what a farmer can achieve is highly dependent on good soil management and climate of the area. It is clear that good soil management can drastically reduce the value of land for agriculture and lead to environmental problems which invariably results into soil degradation and this is termed unsustainable use of land. It has ascertained that about 2,145 million hectares out of 2,900 million hectares total land area in Africa, 72% are problem soils with different production constraints (soil acidity, steeply sloping soils, low fertility, shallow and stony soils, saline and poorly drained soils (Akinsaya et al. 2011). This shows that the level of sustainability of land management practices in Africa. Sustainable land management has been defined as the use of appropriate soil management practices that enables land users to maximize the economic and social benefits from the land while maintaining or enhancing the ecological support functions of the land resources (Akinsaya et al. 2011).
Human activities have either direct or indirect effects on the sustainability of natural resources like land, thereby threatening its continuous productivity. This consequently, affects agricultural production. Also, ever increasing population in the developing countries which result in continually rising of demand for agricultural produce is contributing to the intensification of land use and adoption of technologies that would enhance constant supply of agricultural produce. Attempt by man to meet his food, wood and other resources requirements have destroyed the biodiversity and in order to expand agriculture and forestry, over cropping of some crops has resulted more often, to adoption of appropriate technologies and farm practices which further worsen sustainable land use among farmers. Loss of biodiversity, climate change and land degradation due to population pressure in developing countries, poverty and poor performance of extensive agriculture are such factors that make farmers to have problems in sustainable production activities (Oladoja et al. 2015). Soil is therefore managed in order to conserves agricultural land, biodiversity and food security for the country. Sustaining soil fertility and food security cannot be separated. In addition, it is sometimes noted that some farmers have no or little knowledge about soil management, hence they abandon certain farmland when found unproductive due to some factors which can be controlled provided they are well equipped with knowledge on soil fertility. Dent et al. (2016) opined that if some of the currently used soil management practices are continued, groundwater and food contamination will increase and jeopardize the sustainability of the current land use systems
Sustaining soil fertility has become a major issue for agricultural research and development in rural areas of Africa (Ritung, 2017). Sustaining soil fertility is an essential component in achieving food and livelihood security for the present and future generations. In the past, most research efforts focused on trials to determine the appropriate amount and type of fertilizer needed to obtain the best yields for particular soil types and specific agro-ecological locations. This approach emphasized the use of external inputs and expensive technologies, and often disregarded farmers